package com.lucien.TestDemo;

import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double value = sc.nextDouble();
        System.out.println(String.format("%.6f", test(value)));

    }

    public static double test(double value){
        double temp = value;
        double low = 0;
        double height = value;
        while (low <= height){
            temp = Double.parseDouble(String.format("%.6f", (low + height) /2 ));
            double result = Double.parseDouble(String.format("%.6f", temp * temp));
            if (result == value){
                return temp;
            }else if (result < value){
                low = temp + 0.000001;
            }else {
                height = temp - 0.000001;
            }
        }
        return temp;
    }
}
